A typical data electronics enclosure includes a rigid housing that encloses a variety of components. A data storage system is one type of electronics enclosure. Components in a data storage system include one or more storage media. For example, storage media can be mounted on a spindle motor that causes the media to spin and the data surfaces of the discs to pass under aerodynamic bearing head sliders. The head sliders are supported on an actuator having at least one arm and at least one corresponding suspension that moves across each medium using mechanical energy derived from a voice coil motor. The sliders carry transducers, which write information to and read information from the data surfaces of the media.
With the never-ending need to increase the areal density of a medium, transducer size is constantly shrinking. For example, the width of magnetic transducers, such as reader sensors and write poles are becoming smaller to accommodate the smaller track size on the medium.
In general, both reader sensors and write poles are defined via some type of ion milling, such as ion beam etching (IBE). However, after the reader sensor and the write pole are defined, formation of reaction zones or dead layers of an uncontrolled thickness occur on the sides of the device.
Formation of dead layers can be caused by various reasons. For example, argon beams bombard the sidewalls of the device during ion milling and can cause ion induced physical damage. In another example, after the reader sensor or the write pole is defined by ion milling, the ion milled devices are exposed to atmosphere for transition to other fabricating processes. Due to the atmospheric exposure of the freshly ion milled device, oxygen and water moisture can readily react with the device edges. In yet another example, subsequent oxidation to the sidewalls can occur from an alumina hard mask or other layers of alumina.
Dead layers provide the device with a reduced magnetic moment. In the case of a write pole, dead layers can cause the write pole to write more curved transitions compared to a write pole without dead layers. In the case of a reader, the resistance of the device can vary depending on the thickness of the dead layer and, therefore, the edge effect of the reader is critical. Controlling or eliminating an edge reaction zone in write poles and readers is important for reader/writer performance control.
The discussion above is merely provided for general background information and is not intended to be used as an aid in determining the scope of the claimed subject matter.